High pressure cyclonic separator for turbomachinery

ABSTRACT

The present disclosure generally relates to separating solid particles from an airflow in a gas turbine engine. A separator includes a plurality of vortex chambers arranged about a longitudinal axis of the gas turbine engine, each vortex chamber having a clean air outlet at a first end, a dirty outlet at a second end, and an air inlet transverse to the vortex chamber located at the first end. The separator also includes a sealable collection chamber in fluid communication with the dirty outlet of the each of the plurality of vortex chambers.

INTRODUCTION

The present disclosure generally relates to debris separation in a gasturbine engine.

BACKGROUND

In a gas turbine engine, intake air is compressed by a compressor. Fuelis added to the compressed air and ignited in a combustor. The expandinghot air passes through a turbine and out of a nozzle providing thrust.The turbine converts some of the energy of the expanding hot air intorotational energy for powering the compressor.

Various components of a gas turbine engine may be damaged and/ordegraded when the intake air contains particles such as sand and dust.For example, sand may cause abrasion to compressor blades. As anotherexample, dust may clog cooling holes and/or reduce cooling effectivenessin the turbine resulting in higher turbine temperatures. The damage tothe engine components reduces the efficiency and lifespan of the engine.

Debris removal systems for gas turbine engines generally attempt toremove all types of debris from the intake air using a single separator.While a single separator may reduce the total amount of debris enteringthe components of the gas turbine engine, a single separator may notefficiently remove different types of debris. For example, if the singleseparator is optimized for removing large particles, small particles maypass through the compressor to the combustor and turbine. On the otherhand, if the single separator is optimized for removing smallerparticles, large particles may pass through the compressor, damaging thecompressor. Further, the compressor may pulverize larger particles intosmaller particles that may also damage the turbine.

In view of the above, it can be appreciated that there are problems,shortcomings or disadvantages associated with debris separation in gasturbine engines, and that it would be desirable if improved systems andmethods for separating debris from an airflow in a gas turbine enginewere devised.

SUMMARY

The following presents a simplified summary of one or more aspects ofthe invention in order to provide a basic understanding of such aspects.This summary is not an extensive overview of all contemplated aspects,and is intended to neither identify key or critical elements of allaspects nor delineate the scope of any or all aspects. Its purpose is topresent some concepts of one or more aspects in a simplified form as aprelude to the more detailed description that is presented later.

In one aspect, the disclosure provides a separator for separating solidparticles from an airflow in a gas turbine engine. A separator includesa plurality of vortex chambers arranged about a longitudinal axis of thegas turbine engine, each vortex chamber having a clean air outlet at afirst end, a dirty outlet at a second end, and an air inlet transverseto the vortex chamber located at the first end. The separator alsoincludes a sealable collection chamber in fluid communication with thedirty outlet of the each of the plurality of vortex chambers.

In another aspect, the disclosure provides another separator forseparating entrained solid particles from an airflow in a gas turbineengine. The separator includes a plurality of vortex chambers arrangedabout a longitudinal axis of the gas turbine engine. The separator alsoincludes a sealable collection chamber in communication with a dirtyoutlet of the each of the plurality of vortex chambers. The plurality ofvortex chambers separate at least 70 percent of the entrained solidparticles from the airflow into the sealable collection chamber.

In another aspect, the disclosure provides a method for separatingentrained solid particles from a compressed airflow in a gas turbineengine. The method includes extracting a secondary airflow from thecompressed airflow via a plurality of openings in an impeller shroudsurrounding a compressor impeller. The method also includes separatingthe entrained solid particles from the secondary airflow using aplurality of vortex chambers. The method further includes collecting thesolid particles from a dirty outlet of each of the vortex chambers in asealed collection chamber during operation of the gas turbine engine.

These and other aspects of the invention will become more fullyunderstood upon a review of the detailed description, which follows.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram showing a side section view of aspects ofa conventional gas turbine engine.

FIG. 2 is a diagram illustrating an example classification of debrisparticle sizes.

FIG. 3 is a side section view of an exemplary multi-stage particleseparator.

FIG. 4 is a side section view showing flowpaths within the exemplarymulti-stage particle separator of FIG. 3.

FIG. 5 is a perspective view of a cyclonic separator.

FIG. 6 is an axial cross-sectional view of the cyclonic separator inFIG. 5.

FIG. 7 is transverse cross-sectional view of the cyclonic separator inFIG. 5.

DETAILED DESCRIPTION

The detailed description set forth below in connection with the appendeddrawings is intended as a description of various configurations and isnot intended to represent the only configurations in which the conceptsdescribed herein may be practiced. The detailed description includesspecific details for the purpose of providing a thorough understandingof various concepts. However, it will be apparent to those skilled inthe art that these concepts may be practiced without these specificdetails. In some instances, well known components are shown in blockdiagram form in order to avoid obscuring such concepts.

This written description uses examples to disclose the invention,including the preferred embodiments, and also to enable any personskilled in the art to practice the invention, including making and usingany devices or systems and performing any incorporated methods. Thepatentable scope of the invention is defined by the claims, and mayinclude other examples that occur to those skilled in the art. Suchother examples are intended to be within the scope of the claims if theyhave structural elements that do not differ from the literal language ofthe claims, or if they include equivalent structural elements withinsubstantial differences from the literal language of the claims.Aspects from the various embodiments described, as well as other knownequivalents for each such aspect, can be mixed and matched by one ofordinary skill in the art to construct additional embodiments andtechniques in accordance with principles of this application.

As used herein, the terms “axial” or “axially” refer to a dimensionalong a longitudinal axis of an engine. The term “forward” used inconjunction with “axial” or “axially” refers to moving in a directiontoward the engine inlet, or a component being relatively closer to theengine inlet as compared to another component. The term “aft” used inconjunction with “axial” or “axially” refers to moving in a directiontoward the rear or outlet of the engine, or a component being relativelycloser to the outlet than the inlet.

As used herein, the terms “radial” or “radially” refer to a dimensionextending between a center longitudinal axis of the engine and an outerengine circumference. The use of the terms “proximal” or “proximally,”either by themselves or in conjunction with the terms “radial” or“radially,” refers to moving in a direction toward the centerlongitudinal axis, or a component being relatively closer to the centerlongitudinal axis as compared to another component. The use of the terms“distal” or “distally,” either by themselves or in conjunction with theterms “radial” or “radially,” refers to moving in a direction toward theouter engine circumference, or a component being relatively closer tothe outer engine circumference as compared to another component. As usedherein, the terms “lateral” or “laterally” refer to a dimension that isperpendicular to both the axial and radial dimensions.

FIG. 1 is a schematic cross-sectional diagram of a gas turbine engine 10for an aircraft. The engine 10 has a generally longitudinally extendingaxis or centerline 12 extending forward 14 to aft 16. The engine 10includes, in downstream serial flow relationship, a compressor section22 including a booster or low pressure (LP) compressor 24 and a highpressure (HP) compressor 26, a combustion section 28 including acombustor 30, a turbine section 32 including a HP turbine 34, and a LPturbine 36, and an exhaust section 38. The HP compressor 26, thecombustor 30, and the HP turbine 34 form a core 44 of the engine 10,which generates combustion gases. The core casing 46 surrounds the core44.

A HP shaft or spool 48 disposed coaxially about the centerline 12 of theengine 10 drivingly connects the HP turbine 34 to the HP compressor 26.A LP shaft or spool 50, which is disposed coaxially about the centerline12 of the engine 10 within the larger diameter annular HP spool 48,drivingly connects the LP turbine 36 to the LP compressor 24. Theportions of the engine 10 mounted to and rotating with either or both ofthe spools 48, 50 are referred to individually or collectively as arotor 51.

The LP compressor 24 and the HP compressor 26 respectively include aplurality of compressor stages 52, 54, in which a set of compressorblades 58 rotate relative to a corresponding set of static compressorvanes 60, 62 (also called a nozzle) to compress or pressurize the streamof fluid passing through the stage. In a single compressor stage 52, 54,multiple compressor blades 56, 58 can be provided in a ring and canextend radially outwardly relative to the centerline 12, from a bladeplatform to a blade tip, while the corresponding static compressor vanes60, 62 are positioned downstream of and adjacent to the rotating blades56, 58. It is noted that the number of blades, vanes, and compressorstages shown in FIG. 1 were selected for illustrative purposes only, andthat other numbers are possible. The blades 56, 58 for a stage of thecompressor can mount to a disk 53, which mounts to the corresponding oneof the HP and LP spools 48, 50, with each stage having its own disk. Thevanes 60, 62 mount to the core casing 46 in a circumferentialarrangement about the rotor 51.

The HP turbine 34 and the LP turbine 36 respectively include a pluralityof turbine stages 64, 66, in which a set of turbine blades 68, 70 arerotated relative to a corresponding set of static turbine vanes 72, 74(also called a nozzle) to extract energy from the stream of fluidpassing through the stage. In a single turbine stage 64, 66, multipleturbine blades 68, 70 can be provided in a ring and can extend radiallyoutwardly relative to the centerline 12, from a blade platform to ablade tip, while the corresponding static turbine vanes 72, 74 arepositioned upstream of and adjacent to the rotating blades 68, 70. It isnoted that the number of blades, vanes, and turbine stages shown in FIG.1 were selected for illustrative purposes only, and that other numbersare possible.

In operation, air is supplied to the LP compressor 24, which thensupplies pressurized ambient air to the HP compressor 26, which furtherpressurizes the ambient air. The pressurized air from the HP compressor26 is mixed with fuel in the combustor 30 and ignited, therebygenerating combustion gases. Some work is extracted from these gases bythe HP turbine 34, which drives the HP compressor 26. The combustiongases are discharged into the LP turbine 36, which extracts additionalwork to drive the LP compressor 24, and the exhaust gas is ultimatelydischarged from the engine 10 via the exhaust section 38. The driving ofthe LP turbine 36 drives the LP spool 50 to rotate the LP compressor 24.

Some of the ambient air can bypass the engine core 44 and be used forcooling of portions, especially hot portions, of the engine 10, and/orused to cool or power other aspects of the aircraft. In the context of aturbine engine, the hot portions of the engine are normally downstreamof the combustor 30, especially the turbine section 32, with the HPturbine 34 being the hottest portion as it is directly downstream of thecombustion section 28. Other sources of cooling fluid can be, but is notlimited to, fluid discharged from the LP compressor 24 or the HPcompressor 26.

FIG. 2 is a diagram 200 illustrating an example classification of debrisparticle sizes. The diagram 200 illustrates three classifications ofparticle size, coarse particles 210, fine particles 220, and superfineparticles 230. The coarse particles 210 generally have a mean particlediameter smaller than 1000 micrometers (microns or μm) and generallylarger than 80 μm. The coarse particles 210 may be, for example, sand.The fine particles 220 generally have a mean particle diameter smallerthan 80 μm and generally larger than 5 μm. The superfine particles 230generally have a mean particle diameter smaller than 5 μm. The differentparticle sizes may behave differently within an airflow in a gas turbineengine, have different effects in a gas turbine engine, and damagedifferent components of the gas turbine engine. For example, thebehavior of coarse particles 210 is dominated by particle momentum. Thatis, the coarse particles 210 tend to travel in a line. The behavior offine particles 220, however, may be dominated by centrifugal force. Forexample, fine particles may be pulled to the outside of the gas turbineengine as an air flow swirls. In contrast, the behavior of superfineparticles 230 is dominated by drag force. For example, superfineparticles 230 travel with the airflow and may stick to surfaces of thegas turbine engine. Coarse particles 210 tend to damage compressor rotorassemblies and impellers. In particular, the coarse particles 210 causeburrs and rollover on the leading edge of impellers and also round thetips as the coarse particles 210 abrade the spinning parts. Superfineparticles 230 tend to accumulate on or within the combustor 30 or theturbine 34, 36. For example, superfine particles 230 may accumulatewithin cooling holes of the turbine blades and eventually block thecooling holes, leading to a rise in turbine temperature.

In an aspect, an inlet particle separator removes at least some of thecoarse particles 210 before they enter the compressor section 22.Further details of an example inlet particle separator are described incopending U.S. application Ser. No. 15/002,839, filed Jan. 21, 2016,titled “INLET PARTICLE SEPARATOR FOR A TURBINE ENGINE,” and U.S. patentapplication Ser. No. ______, titled “MULTI-STATION DEBRIS SEPARATIONSYSTEM” with attorney docket number 283711/037216.00047, filed Jul. 20,2016, both of which are incorporated herein by reference in theirentirety.

FIG. 3 is a side section view of a multi-stage separator 340. Themulti-stage separator 340 is located downstream from the compressorsection 22, which compresses the inlet air flow and provides acompressed air flow. The compressor section 22 also pulverizes largerparticles remaining within the input airflow into smaller particles(e.g., super-fine particles). The multi-stage separator 340 includes oneor more separators that bleed a portion of the compressed airflow forvarious uses. For example, the multi-stage separator 340 includes acyclonic separator 342 and a clean air offtake 344. In an aspect, themulti-stage separator 340 is adapted to remove smaller particles (e.g.,fine and superfine particles) from the compressed airflow. Themulti-stage separator 340 is designed to remove superfine particulatepassing through the compressor. Preferably at least 70%, more preferably80%, of the superfine material is removed at this stage.

The multi-stage separator 340 receives a compressed air flow from thecompressor 314. In particular, the compressor impeller 510 is a laststage of the compressor section 22. As illustrated, the compressorimpeller 510 is a centripetal impeller that further compresses theairflow and pushes the air in a radially distal direction against animpeller shroud 514. The impeller shroud 514 defines a portion of theflowpath having a reduced cross-section. As the compressed airflowleaves the compressor impeller 510, the airflow accelerates. Thecompressor impeller 510 and the impeller shroud 514 also turn theairflow in a radial distal direction. A compressor case 518 supports theimpeller shroud 514 and also defines a space outside of the mainflowpath between the compressor case 518 and the impeller shroud 514.

The multi-stage separator 340 includes a cyclonic separator 520, adiffuser 530, a clean air offtake 540, an optional heat exchanger 550,and a deswirler 560. The cyclonic separator 520 includes an intake 516located along a radially distal surface of the impeller shroud 514. Theradially distal surface defines a surface of the flowpath as thecompressor impeller 510 turns the airflow in the radially distaldirection. The intake 516 for example, includes a cowl having a at leastone opening within the radially distal surface of the impeller shroud514. For example, the at least one opening may be a continuous slit or aplurality of openings. Because the solid particles entrained within thecompressed airflow 504 are mostly superfine particles 230, the dragforce tends to dominate, and the particles concentrate along theradially distal surface of the impeller shroud 514. A portion of thecompressed airflow enters the cyclonic separator 520 via the pluralityof openings, carrying the solid particles into the cyclonic separator520.

In an embodiment, the cyclonic separator 520 includes a plurality ofcyclonic chambers surrounding the impeller shroud 514. The cyclonicseparator 520 is adapted for separating superfine particles because thedrag force causes superfine particles to remain in an outer vortex whilerelatively clean air can be extracted from an inner vortex. Therelatively clean air exits through an outlet to form a clean airflowwhile the solid particles are collected in a collection chamber. Thecollection chamber is a sealable collection chamber that is sealedduring operation of the gas turbine engine 300. Accordingly, thecompressed airflow 504 does not lose flow to a vent. The collectionchamber is vented during a shutdown, cleaning, or startup operation. Forexample, the collection chamber is vented when an air starter is used tostart the gas turbine engine 300.

The diffuser 530 conveys a first remaining portion of the compressedairflow 504 in the radially distal direction towards a deswirler 560.The diffuser 530 is supported by the diffuser case 524. The diffusercase 524 and the diffuser 530 define a flowpath for a cleaned airflowfrom the cyclonic separator 520. In other words, the cleaned air fromthe cyclonic separator 520 flows within the diffuser case 524 withoutreentering the primary airflow within the diffuser 530. Ducts orpassages between walls of a multi-walled component (e.g., the deswirler560) route the cleaned airflow to an optional heat exchanger 550 anddownstream cooling and/or pressurization uses.

The deswirler 560 is located about a radially distal edge of thediffuser 530. The deswirler 560 turns the airflow in an axially aftdirection and reduces lateral movement of the airflow. A radially distalsurface of the deswirler 560 is defined in part by an engine mount 552that forms a radially distal wall of the gas turbine engine 300. Theclean air offtake 540 is located at a radially proximal surface of thedeswirler 560. For example, the clean air offtake 540 includes anopening within the radially proximal surface of the deswirler 560forming an inlet to the clean air offtake 540. Due to centrifugal forceand drag forces, the remaining solid particles entrained within theprimary airflow tend to drag along the radially distal surface of thediffuser 530 and the engine mount 552. Accordingly, the clean airofftake 540 separates a portion of relatively clean air from thecompressed primary airflow. In an aspect, the clean air offtake 540further includes a deflector partially covering the inlet to the cleanair offtake 540. The deflector deflects solid particles away from theinlet to the clean air offtake 540 to provide a cleaner airflow withinthe clean air offtake 540.

The clean air offtake 540 also includes ducts or passages that form asecondary flowpath to an optional heat exchanger 550 and downstreamcooling uses. A remaining portion of the compressed primary airflowtravels through the deswirler 560 into the combustor 316.

The optional heat exchanger 550 cools one or more cleaned airflows. Forexample, the heat exchanger 550 is in fluid communication with thecyclonic separator 520 or the clean air offtake 540. The heat exchanger550 includes separate flowpaths for the one or more cleaned airflows andfor a relatively dirty waste airflow. For example, the waste airflow maybe a bypass airflow or ambient air. The cleaned airflows may be a firstcleaned airflow from the cyclonic separator 520 or a second cleanedairflow from the clean air offtake 540. Heat from the cleaned air flows,which are compressed, is transferred into the dirty airflow, which isthen vented.

FIG. 4 is a side section view showing airflows within the exemplarymulti-stage separator 340. The compressor 314 provides a compressedairflow 504 from the compressor impeller 512 towards the impeller shroud514, where the cyclonic separator 520 bleeds of a portion of thecompressed airflow 504 and produces a first cleaned airflow 610. Aremaining portion of the compressed airflow 504 travels through thediffuser 530 until the clean air offtake 540 bleeds off a second cleanedairflow 620. The remaining portion of the compressed airflow 504 becomesthe flowpath airflow 630, which flows to the combustor 316. The flowpathairflow 630 enters the combustor 316 via a fuel nozzle 640, where theflowpath airflow 630 is mixed with fuel and ignited. The flowpathairflow 630 also enters the combustor 316 via openings in the combustorliner 642.

The second cleaned airflow 620 may be the cleanest airflow. For example,the second cleaned airflow 620 may have a lower concentration of solidparticles than the compressed airflow 504, the first cleaned airflow610, or the flowpath airflow 630. The second cleaned airflow 620 may beused to cool a first stage of a high pressure turbine 320. The secondcleaned airflow 620 flows through an optional heat exchanger 550 on itsway to the high pressure turbine 320. Ducts or passages within themulti-walled components of the gas turbine engine 300 route the secondcleaned airflow 620 to an accelerator 564. The second cleaned airflow620 is passed from the accelerator 564 through the turbine blades viacooling holes and provides for thin film cooling of the turbine blades.

The first cleaned airflow 610 is routed to a second stage of the highpressure turbine 320. The first cleaned airflow 610 may be of lowerpressure than the second cleaned airflow 620. Ducts or passages withinthe multi-walled components of the gas turbine engine 300 route thefirst cleaned airflow 610 to the second stage of the high pressureturbine via an outer shell of the combustor 216 and via a bearing sump566. The second stage of the high pressure turbine 320 may operate at alower temperature than the first stage of the high pressure turbine andbe less susceptible to damage from solid particles.

FIG. 5 is a perspective view of a cyclonic separator 700. The cyclonicseparator 700 is an example of the cyclonic separator 520. It should beappreciated, however, that a cyclonic separator 700 may be located in adifferent position within the core 302. For example, the cyclonicseparator 700 may be located before the compressor 314. The cyclonicseparator 700 includes a cowl 710 including a plurality of openings 720in fluid communication with a plurality of vortex chambers 740. A rim730 defines an end of the cowl 710. The vortex chambers 740 are in fluidcommunication with a collection chamber 750, which also defines a bodyof the cyclonic separator 700. A flange 760 is connected to thecollection chamber 750 to provide structural support and attachmentpoints for the cyclonic separator 700.

The cowl 710 defines radially distal surface of a flowpath within thecore 302. In an embodiment, the cowl 710 is the radially distal surfaceof the impeller shroud 514. That is, the cowl 710 helps restrict theflowpath of the compressed air from the compressor 314. Moreover,because the compressed air is rotating laterally within the cowl 710,particles entrained within the compressed air experience centrifugalforce causing the particles to contact the cowl 710. In an embodiment,the cowl 710 includes ridges 712 that increase a drag force on theparticles and help slow the axial movement of the particles.

The plurality of openings 720 are located toward an axially distal endof the cowl 710. In an embodiment, the openings 720 are axiallyelongated. The size, shape, and number of the openings 720 may be variedto bleed off a desired portion of the compressed air. For example, thenumber of openings 720 may be between approximately 10 and 100,preferably approximately 60. Each opening 720 is in fluid communicationwith a respective vortex chamber 740. As will be described in furtherdetail below, the opening 720 leads to an inlet of the vortex chamber740. The vortex chamber 740 creates an outer vortex that pulls solidparticles into the collection chamber 750 and an inner vortex that pullsclean air to an outlet of the vortex chamber 740.

The collection chamber 750 includes one or more hollow regions thatreceive particles from the vortex chambers 740. In an embodiment, thecollection chamber 750 is sealable. For example, the collection chamber750 includes one or more vents 754 that may be opened or closed. Thevents 754 are closed during operation of the gas turbine engine 300.Accordingly, the collection chamber 750 retains the collected particlesduring operation. Moreover, because the collection chamber 750 is notvented during operation, the collection chamber 750 does not cause aloss in pressure. The collection chamber 750 is vented during ashutdown, cleaning, or startup operation. During a startup operation,venting via the collection chamber 750 helps reduce backpressure on thecompressor 314.

FIGS. 6 and 7 illustrate further details of the cyclonic separator 700.FIG. 6 is an axial cross-sectional view of the cyclonic separator 700and one of the vortex chambers 740. FIG. 7 is transverse cross-sectionalview of the cyclonic separator 700. The opening 720 is in fluidcommunication with the vortex chamber 740 via a curved passage 722. Thecurved passage 722 causes an airflow 724 to bend, starting a cyclonicmotion. As best seen in FIG. 6, the curved passage 722 communicates witha first end of the cyclonic chamber through an outer wall 742 thatdefines the vortex chamber 740. The outer wall 742 has a generallyconical shape and extends longitudinally to an open second end 752. Acentrally located vortex finder 744 extends longitudinally from thefirst end of the vortex chamber 740. The vortex finder 744 defines anexit flowpath 748. The vortex finder 744 includes a cylindrical portionhaving a solid wall located adjacent the first end of the vortex chamber740 and a conical portion 746 having a perforated wall extendinglongitudinally from the cylindrical portion.

The second end 752 of the vortex chamber 740 extends in a radiallyproximal direction into the collection chamber 750. The second end 752is located near a radially proximal surface 756 of the collectionchamber 750. The vortex chamber 740 may also be angled laterally.

In operation, the airflow 724 of compressed air enters the opening 720and follows the curved passage 722 into the vortex chamber 740. Theouter wall 742 and the cylindrical portion of the vortex finder 744continue to bend the airflow 724 to form an outer vortex spiraling aboutthe vortex finder 744. As the airflow 724 reaches the conical portion746, solid particles entrained in the airflow 724 tend to move to theouter wall 742 due to centrifugal and drag forces. Clean air near thecenter of the vortex chamber 740 enters the vortex finder 744 via theperforations and via the inner vortex opening. The dirty air entrainingthe solid particles continues to move longitudinally and is dischargedvia the second end 752 into the collection chamber 750. The lateralangle of the vortex chambers 740 imparts a circular movement to the airwithin the collection chamber 750. The solid particles are drawn towardthe radially distal wall 758 of the collection chamber rather thanreentering the second end 752. The exit flowpath 748 provides a cleanairflow, for example, the first cleaned airflow 610.

The components of the gas turbine engine 300 may be manufactured usingan additive manufacturing (AM) process. AM encompasses variousmanufacturing and prototyping techniques known under a variety of names,including freeform fabrication, 3D printing, rapid prototyping/tooling,etc. AM techniques are capable of fabricating complex components from awide variety of materials. Generally, a freestanding object can befabricated from a computer aided design (CAD) model. A particular typeof AM process, direct metal laser melting (DMLM), uses an energy beam,for example, an electron beam or electromagnetic radiation such as alaser beam, to sinter or melt a powder material, creating a solidthree-dimensional object in which particles of the powder material arebonded together. AM may be particularly applicable for manufacturing,for example, the cyclonic separator 700, which includes multipleconcentric and coaxial subcomponents. In an aspect, the cyclonicseparator 700 may be fabricated in a layer-by-layer manner along thelongitudinal axis. The AM process may fabricate the cyclonic separator700 as an integrated structure.

This written description uses examples to disclose the invention,including the preferred embodiments, and also to enable any personskilled in the art to practice the invention, including making and usingany devices or systems and performing any incorporated methods. Thepatentable scope of the invention is defined by the claims, and mayinclude other examples that occur to those skilled in the art. Suchother examples are intended to be within the scope of the claims if theyhave structural elements that do not differ from the literal language ofthe claims, or if they include equivalent structural elements withinsubstantial differences from the literal language of the claims.Aspects from the various embodiments described, as well as other knownequivalents for each such aspect, can be mixed and matched by one ofordinary skill in the art to construct additional embodiments andtechniques in accordance with principles of this application.

1. A separator for separating solid particles from an airflow in a gasturbine engine, comprising: a plurality of vortex chambers arrangedabout a longitudinal axis of the gas turbine engine, each vortex chamberhaving a clean air outlet at a first end, a dirty outlet at a secondend, and an air inlet transverse to the vortex chamber located at thefirst end; and a sealable collection chamber in fluid communication withthe dirty outlet of the each of the plurality of vortex chambers.
 2. Theseparator of claim 1, wherein the sealable collection chamber is adaptedto be sealed during operation of the gas turbine engine.
 3. Theseparator of claim 1, wherein the sealable collection chamber is adaptedfor venting during at least one of an engine start operation, an engineshutdown operation, and a cleaning operation.
 4. The separator of claim3, wherein the venting relieves back pressure against the compressorduring the engine start operation.
 5. The separator of claim 3, whereineach vortex chamber comprises a vortex finder within the vortex chamberseparating the air inlet from the clean air outlet.
 6. The separator ofclaim 5, wherein each vortex finder is perforated.
 7. The separator ofclaim 5, wherein each vortex finder separates an outer vortex fed by therespective air inlet from an inner vortex of relatively clean air. 8.The separator of claim 1, wherein the separator is located downstreamfrom a compressor.
 9. The separator of claim 1, further comprising acowl in fluid communication with an output airflow from the compressor,the cowl including a plurality of openings, each of the openings influid communication with the air inlet of a respective cyclonicseparator.
 10. The separator of claim 9, wherein the cowl is locatedwithin an impeller shroud arranged circumferentially about a final stagecentripetal impeller of the compressor.
 11. The separator of claim 9,wherein an airflow within each air inlet has a higher density ofparticles than the output airflow from the compressor.
 12. The separatorof claim 1, wherein the clean air outlet is in fluid communication witha cooling system.
 13. The separator of claim 12, wherein the coolingsystem is a high pressure turbine second stage cooling device.
 14. Theseparator of claim 12, wherein the cooling system includes cooling holeswithin a turbine rotor.
 16. The separator of claim 1, wherein the solidparticles have an average particle size less than 5 micrometers.
 17. Theseparator of claim 1, wherein an inside wall of the vortex chamberdeflects air circumferentially to form an outer vortex.
 18. A separatorfor separating entrained solid particles from an airflow in a gasturbine engine, comprising: a plurality of vortex chambers arrangedabout a longitudinal axis of the gas turbine engine; and a sealablecollection chamber in communication with a dirty outlet of the each ofthe plurality of vortex chambers, wherein the plurality of vortexchambers separate at least 70 percent of the entrained solid particlesfrom the airflow into the sealable collection chamber.
 19. The separatorof claim 18, wherein the plurality of vortex chambers separate at least80 percent of the entrained solid particles from the airflow into thesealable collection chamber.
 20. A method for separating entrained solidparticles from a compressed airflow in a gas turbine engine, comprising:extracting a secondary airflow from the compressed airflow via aplurality of openings in an impeller shroud surrounding a compressorimpeller; separating the entrained solid particles from the secondaryairflow using a plurality of vortex chambers; and collecting the solidparticles from a dirty outlet of each of the vortex chambers in a sealedcollection chamber during operation of the gas turbine engine.
 21. Themethod of claim 20, wherein separating the entrained solid particlescomprises separating at least 70 percent of the entrained solidparticles from the secondary airflow.
 22. The method of claim 21,wherein separating the entrained solid particles comprises separating atleast 80 percent of the entrained solid particles from the secondaryairflow.
 23. The method of claim 20, further comprising providing acleaned airflow from a clean outlet of each of the vortex chambers to acooling system.